Study of Catechol and Resorcinol Adsorption Mechanism through Granular Activated Carbon Characterization, pH and Kinetic Study

Abstract

The present article reports results of the studies on adsorptive removal of catechol and resorcinol from aqueous solution by granular activated carbon (GAC). Physico-chemical characterization including surface area, X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR) of the GAC before and after catechol and resorcinol adsorption have been done to understand the adsorption mechanism. Bulk density and heating value of GAC were found to be 725 kg/m3 and 8.26 MJ/kg, respectively. The BET surface area was 977.6 m2/g whereas the BET average pore diameter was 18.79 Å. Different experimental parameters like initial pH, initial dosage, contact time, and initial concentration were evaluated for their effect on the adsorption of catechol and resorcinol onto GAC. The kinetics of adsorption was found to be described by the pseudo-second order equation. Results of the intra-particle diffusion model show that the pore diffusion is not the only rate limiting step. The effective diffusion coefficient of catechol and resorcinol were of the order of 2.9 × 10−10 and 2.2 × 10−10 m2/s.